Hybrid drives for vehicles are conventional. In the hybrid drives addressed here, an internal combustion engine is combined with at least one electric motor/generator, so that a plurality of drive sources for the vehicle are available. According to requirements specified by a vehicle driver, the drive sources may optionally feed their driving torque into a power train of the vehicle. This results, in a conventional manner in various drive configuration possibilities, depending on concrete driving situations, which are used in particular to improve driver comfort and to reduce energy use, as well as to reduce pollutant emission.
In hybrid drives for vehicles, serial arrangements, parallel arrangements and mixed arrangements of an internal combustion engine and electric motor/generators are conventional. Depending on the arrangement, the electric motor/generators may be connected to the power train of the engine directly or indirectly. For the operative linkage of the internal combustion engine and/or the electric motor/generators it is conventional to arrange them so that they are operatively linkable with each other using gearing, for example planetary gears and the like, and clutches.
Optimum implementation of a driver's request for propulsion power from the hybrid drive requires coordinated activation of the propulsion motors of the hybrid drive, which is accomplished, as is conventional, by a device known as a control unit. The propulsion motors may be activated on the basis of a setpoint operating state of the hybrid drive to be determined by the control unit. The objective in determining this setpoint operating state is in particular low fuel consumption, dynamic drivability of the vehicle and low pollutant emission.
Furthermore, it is generally conventional to equip vehicles with an electronically activatable braking system, for example an electrohydraulic or electromechanical brake.